Batteries are used in various fields, for example, electronic devices such as a mobile phone and a personal computer, vehicles such as a hybrid vehicle and an electric vehicle. For example, a battery used in a vehicle field is configured such that a power generating element is enclosed in a casing of a can body and a lid member is welded to an opening of the casing to seal the opening. The lid member is formed with a through hole penetrating therethrough in a thickness direction of the lid member, and an insertion part of a current collector terminal member electrically connected to the power generating element extends out through the through hole.
As a method for fixing the current collector terminal member to the lid member, for example, Patent Document 1 discloses a technique that an insertion part of a cylindrical current collector terminal member is inserted through openings formed one each in an external connecting terminal, an insulator, the lid member, and a gasket, and further an upper end of the insertion part is deformed by caulking or riveting to extend radially outward relative to the center axis of the insertion part, providing temporary joining, and then the extended upper end of the insertion part and an upper surface of the external connecting terminal are welded and fixed to each other. In the battery disclosed in Patent Document 1, the gasket seals between the lid member and the current collector terminal member to suppress gas leakage from the opening of the lid member through which the insertion part of the current collector terminal member is inserted through.